Elevator systems



Aug- 6, 1957 P. c. Kr-:IPER 2,801,710

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United States Patent() 10 Claims. (Cl. 187-29) This invention relates toelevator systems and it has particular relation to elevator systemswhich are designed for operation without car attendants.

Although aspects of the invention may be employed in elevator systemshaving car attendants, the invention is particularly desirable forelevator systems of the automatic type which do not have car attendants.For this reason, the invention will be discussed with particularreference to such operatorless systems.

When an elevator car in an operatorless system stops at a landing, suchas a floor of a building or structure, it is the practice to hold theelevator car at the floor for a substantial time in order to permitloading and unloading of the elevator car, This time is referred to as anon-inter-v ference time. In the prior art systems, the non-interferencetime may be of the order of or more seconds for each stop.

The non-interference time may be varied in accordance with therequirements for each of the iloors at which a stop is made. To thisend, the elevator system is designed to hold an elevator car at a oor atwhich the elevator stops for a non-interference substantial time, suchas 5 seconds.

The non-interference time for a car call may diier from that employedfor a iloor call. Thus, if a passenger within the elevator car registersa call for a floor, the elevator car may be held at such door for anon-interference timeof the order of say three seconds. However, if theelevator car stops in response to a iloor call registered by anintending passenger at one of the intermediate oors, a longernon-interference time, to allow a passenger to walk to the car that isstopping from the farthest point of the corridor, such as 5 to 7 secondsmay be employed.

In one system to which the invention may be applied a substantialnon-interference time is provided for each stop of the elevator car.However, upon movement of a passenger into or out of the elevator car,the non-interference time is reset to a smaller value which may belarger for a stop made in response to a floor call than for a stop madein response to a car call. For example, if the elevator car stops at aoor in response to a car call, the elevator car door opens and remainsopen for a noninterference time of the order of five seconds if no oneleaves or enters the elevator car. However as soon as a person leaves orenters the elevator car, the non-interiCC elevator car door may beconditioned to open each time a passenger attempts to enter or leave theelevator car before the elevator car door completely closes. When thishappens, the door dose not start to close until a short time such asone-half second after the last passenger has passed through the doorway.A system of this type is disclosed in my copending application, SerialNo. 406,706, tiled January 28, 1954, of which this is a continuation inpart, inthe Santini patent application, Serial No. 427,476, led May 4,1954, and in the Santini et al. patent application, Serial No. 427,475,tiled May 4, 1954, all of which are assigned to the same assignee,

lf the elevator car stops in response to a registered iloor call at anintermediate tloor, the elevator car door again is opened and remainsopen for a substantial non-inter ference time, such as tive seconds.However, if a person enters or leaves the elevator car, thenon-interference time is reset for a smaller value, such as two seconds.If succeeding persons enter or leave the elevator car at close enoughintervals, the non-interference time is reset for each of the personsfor a time which may be of the order of one-half second in order todelay the reclosure of the door.

If thev elevator car stops at an intermediate tloor in response to aregistered tloor call and is assigned to reverse at such oor, the doormay open for a non-interference time of the order of five seconds. Inthis case, entry of a person into the car or departure of a passengerfrom the car may reset the non-interference time to a smaller value ofthe order of one-half second. Each succeeding person entering or leavingthe elevator car within suitable intervals may reset thenon-interference time for an interval of the order of one-half second todelay reclosure of the door.

The movement of a passenger or an intending passenger into or out of theelevator car can be determined by transmitting energy into the passagetraversed by such passenger. Interruption of such energy path by apassenger is ascertained by a suitable detector.

In some cases, a passenger may attempt to prevent the closure of thedoor for an unreasonably long time by standing in the path of thetransmitted energy. `If the energy is interrupted for an unduly longperiod, such as four seconds, a closing movement of the door isinitiated promptly at the close of such period. Desirably the door V maybeprovided with a protective edge which initiates the ference time isreset to a value of the order of one-half stopping or reopening of thedoor if the door reaches a person located in the closing path of thedoor. If as the door reopens the path for the energy is reestablishedthe `door will remain open for the required one-half second and will notstart to reclose as long as the path is interrupted at less thanone-half second intervals.

After the movement into or out of the elevator car starts, successiveloads or. passengers ordinarily follow the first load or passengerrapidly. Each load yor passengerafter the trst one resets thenon-interference time for an additional small time of the order ofone-half second. Consequently, waste time is substantially eliminatedand the etliciency of the elevator system is mate- .rially improved.

At terminal lloors, it may be desirable to control the departure ofelevator cars by a suitable dispatcher for the purpose of maintainingadequate spacing of the elevator cars. In such a case, the variablenon-interference time is still desirable for the intermediate iloors orlandings served by each elevator car. If the car is loading orIunloading after a closing operation of the elevator car door isinitiated by the dispatcher, the closure of the door may be prevented byoperation of the detector.

In a suitable system, an elevator car is provided with a passage throughwhich load, such as a passenger, may enter and leave the elevator car.The passage may be exposed or closed by a door which is automaticallyopened as the elevator car reaches a predetermined load transferposition which ordinarily is a landing or floor of a building. Uponexpiration of the noninterference time, the door may be closed for thepurpose of permitting departure of the elevator car.

A signal or energy is established or transmitted across the passage. Adetector is provided which is responsive to a function of the signal orenergy. For example, the detector may be responsive t-o the presence orabsence of radiant energy. If a4 load, such as a passenger, enters thearea through which the radiant energy is projected, the detector sensesthe presence of such load. The detector, in turn, controls mechanismwhich, in response to the movement of the load through the passage,resets the non-interference time in the manner previously described. Ifthe detector receives no radiant energy for more than a predeterminedtime the door may be promptly closed.

If the closure of the door is prevented for more than a reasonable time,a closing force may be exerted on the door continuously until the doorcloses. The system may be so arranged that the closing force is exertedunless safety edges on both sides of the dooi` opening are operated. v v

If the elevator car reaches a oor, such as a street floor, with asubstantial load to be discharged, the departing passengers prevententry of the passengers waiting to board the elevator car. The timeavailable for the entering passengers may be inadequate.

In accordance with the invention, a substantial delay is provided in thedeparture of the elevator car from a iloor such as the street floor orin closure of the car door at such floor following the departure of eachpassenger from the elevator car. However, time transfer means controlledby a boarding passenger provides a delay in the departure of theelevator car or in closure of the car door following the entry of eachboarding passenger which has a time value materially less than theaforesaid substantial delay. This provides adequate time for the iirstboarding passenger without requiring excessive delays for succeedingboarding passengers.

The time transfer means may be operated by directional means responsiveto the entry of a passenger into the car but insensitive to departure ofpassengers from the car. Such directional means are shown in theaforesaid Santini patent application.

In a preferred embodiment of the invention, the time transfer meansisresponsive to operation of car-call registering means by a boardingpassenger to register a call for another floor. It is, therefore, anobject of the invention to provide an improved elevator system having aminimum of lost time at each elevator car stop.

It is a further object of the invention to provide an improved elevatorsystem having a minimum non-interference time for an elevator car whichis sufficient to permit unloading of an elevator car followed by loadingthereof.

It is another object of the invention to provide an elevator systemwherein departure of an elevator car from a floor is delayed for asubstantial time for each passenger leaving the car and wherein meanscontrolled by a boarding passenger provides a delay in departure of theelevator car for each boarding passenger which is smaller than saidtime.

Other objects of the invention will be apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

Figure 1 is a schematic view with parts in elevation and parts brokenaway of an elevator system which may embody the invention;

Fig. 1A is a view in section showing an elevator car employed in Fig. lassociated with a hoistway;

Figs. 2, 3 and 4 are schematic views including circuits 4 instraight-line form of a control system embodying the invention;

Fig. 5 is a schematic view including circuits in straightline form of amodied control system embodying the invention; and

Figs. 2A, 3A and 4A are key representations of electromagnetic relaysand switches employed in the circuits of Figs. 2, 3 and 4. If Figs. 2, 3and 4 are horizontally aligned respectively with Figs. 2A, 3A and 4A, itwill be found that coils and contacts of the switches and relaysappearing in the key representations are horizontally aligned with thecorresponding coils and contacts shown in these circuits.

Although the invention may be incorporated in an elevator systememploying various numbers of elevator cars serving buildings orstructures having various numbers of oors, the invention can bedescribed adequately with reference to an elevator system having fourelevator ventions have been adopted. The elevator cars will beidentilied by the reference characters A, B, C and D. Since the circuitsfor the cars are similar, substantially complete circuits areshown forthe cars A and B. Components associated with the cars C and D arediscussed only as required.

Components associated with the elevator cars B, C and D which correspondto a component of the elevator car A are identified by the same`reference character employed for the component of the elevator car Apreceded by the letters B, C and D, respectively. For example, thereferencev characters U, BU, CU and DU designate up switches,respectively, for the elevator cars A, B, C and D. The discussion willbe directed primarily to the apparatus and circuits for the elevator carA.

The various relays and switches employed in the circuits may have breakor back contacts which are closed when the relay is deenergized anddropped out. The break contacts are open when the relays or switches areenergized and picked up.

The relays and switches also may have front or make contacts which areopened when the switches and relays are deenergized and dropped out.These contacts are closed when the 4switches and relays are energizedand picked up. In the drawings the various switches and relays are shownin so far as possible to their deenergized and dropped-out conditions. v`Each set of the contacts associated with a relay or switch isidentified by the reference character associated with the relay orswitch followed by a numeral identify'- ing the specific set ofcontacts. Thus, the reference characters U1, U2 and U3 designated,respectively, the first, 'second and third sets of contacts of the upswitch U.

In order to facilitate the presentation of the invention, the apparatusshown in the figures will be briefly set forth, and the operation of thecomplete system thereafter will be discussed. The system includes linpart the following apparatus:

p APPARATUS SPECIFIC TO CAR A Y'5 80--main starting relay L-car-positionrelay N-loading relay S-auxiliary starting relay 50A-car-call detectorrelay 40-door relay 45-door-control relay DC-door-close solenoidDO-door-open solenoid SR-detector relay LWA, NU, NUA, 70HT, SRT-timedelay relays 300-eXpediter relay I--reversal relay APPARATUS COMMON TOALL CARS 2DR to SDR-down floor-call storing relays ZUR to 4UR-upfloor-call storing relays Figure 1 Fig. 1 illustratesthe structuralrelationships of the elevator cars A, B and lassociated apparatus withreference to the building structure which the elevator cars are intendedto serve.

The elevator car A and a counterweight are secured to opposite ends of arope or cable 11 which passes over a sheave 13. The sheave 13 is mountedon the shaft 14 of an elevator driving motor 15. The shaft 14 alsocarries a brake drum 16 with which a brake 17 of the conventionalspring-applied electrically-released type is associated. The motor 15 issecured to the oor 18 of a penthouse located in the structure which theelevator car is intended to serve.

In order to simplify the association of control circuits with theelevator car A, a control device 19 is provided which is operated inaccordance with a function of the movement of the elevator car A. In thespeciiic embodiment of Fig. 1, the control device takes the form of afloor selector which includes an insulating panel 20 and a brushcarriage 21. A screw 22 is mounted for rotation relative to the panel20. This screw conveniently may be coupled through suitable gearing tothe shaft 14 for rotation in accordance with movement of the elevatorcar A.

The brush carriage 21 is in threaded engagement with the screw 22. Asthe elevator car A moves upwardly, the brush carriage 21 is movedupwardly but at a rate much slower than the rate of movement of theelevator car.V Similarly, when the elevator car A moves downwardly, thebrush carriage 21 also moves downwardly at a slower rate.

The panel 2() carries a plurality of contact segments which areinsulated from each other. Thus, the contact segments a2 to a5 arearranged in a -row on the panel 20. As the elevator car proceedsupwardly from the basement, a brush 23 mounted on the carriage 21successively engages the contact segments a2 to a5, as the elevator carapproaches respectively the floors 2 to 5 of the structure. AIt will beunderstood that the contact segments a2 to a5 are spaced from each otherin accordance with the spacings of the oors. As will be pointed outbelow, these contact segments are employed with circuits controlling thestopping of the elevator car during up travel in response to car calls.

As a further example, the panel 20 has a single contact segment e1 whichis engaged by a brush 24 mounted on the carriage 21 only when theelevator car A is adjacent the first or dispatching oor. As will bepointed out below, this contact segment is employed in controlling theoperation of a dispatching device.

It will be understood that a number of rows of contact segments and anumber of brushes may be employed in the floor selector. However, theforegoing discussion is believed sutiicient to illustrate the mechanicalrelationships of these contact segments and brushes.

Certain apparatus is mounted on or in the elevator car A. Thus, car-callbuttons 2c to 5c are provided for registering car calls for the second,third and fourth oors, respectively.

A slowdown-inductor relay E is provided for the purpose of initiating aslowdown of the elevator car A as it approaches a oor at which it is tostop. The inductor relay may be of conventional construction andincludes two sets of break contacts E1 and E2. When the coil of theinductor relay E is energized, the contacts remain in the positionsillustrated in Fig. l until the relay is adjacent an inductor platelocated in the hoistway of the elevator car A. For example, when thecoil of the inductor relay E is energized and the inductor relay isadjacent the magnetic plate UEP for the second floor, the magneticcircuit is completed, which results in opening of thebreak contacts E1.When open, the contacts remain open until the coil of the inductor relayE is deenergized. The inductor plate UEP is positioned to be reached bythe inductor relay E as the elevator car approaches the second floor forthe purpose of initiating slowdown of the elevator car. It will beunderstood that a similar inductor plate is similarly associated witheach of the floors at which the elevator car is required to stop duringup travel.

If the coil of the inductor relay E is energized during down travel ofthe elevator car, and if the relay reaches the inductor plate DEP forthe second licor, a magnetic circuit is completed which results inopening of the break contacts E2. When opened, the contacts remain openuntil the coil is deenergized. The inductor plate DEP is so positionedthat it initiates slowdown of the elevator car A a suitable distancefrom the second floor. A similar inductor plate would be similarlyassociated with each of the floors at which the elevator car A is tostop during down travel.

The elevator car A also carries a stopping inductor relay F which issimilar in construction to the inductor relay E. This relay is employedfor initiating a stopping operation of the elevator car A. The stoppinginductor relay F cooperates with inductor plates UFP and DFP in a mannerwhich will be clear from the discussion of the cooperation of theslowdown inductor relay with the inductor plates UEP and DEP. If thecoil of the relay F is energized and if the elevator car is to stop atthe seco-nd iioor while traveling up, when the inductor relay F reachesthe inductor plate UFP a magnetic circuit is completed which results inopening of the break contacts F1. This initiates a stopping operation ofthe elevator car. An inductor plate similar to the plate UFP issimilarly associated with each of the floors at which the elevator car Ais to stop during up travel thereof. If the elevator car A during downtravel is to stop at the second floor, the coil of the stopping inductorrelay F is energized, and when the inductor relay reaches the inductorplate DFP for the second floor, a magnetic circuit is completed whichresults in opening of the contacts F2. This initiates a stoppingoperation of the elevator car A. l't will be understood that an inductorplate similar to the inductor plate DFP is similarly associated witheach of the oors at which the elevator A is to stop during down travelthereof.

The elevator car A also carries a mechanical switch 63 which ispositioned to be operated by cams 26 located in the hoistway associatedwith the elevator car. The mechanical switch 63 normally is closed andis opened by a cam 26 when the elevator car A is adjacent the first ordispatching oor and by a similar cam when the car is at the upperterminal oor. It will be understood that other mechanical switches maybe operated in a similar manner by the elevator car A.

An intending passenger on the fourth floor may register a floor call forelevator car service in the up direction by pressing a button of apush-button switch 4U. A similar push-button switch is located at eachof the i11- '7 termediate floors from which an intending passenger maydesire to proceed in an up direction.

If the intending passenger at the fourth floor desires to proceed in adown direction, he may press the button of a push-button switch 4Dlocated at the fourth floor. A similar push-button switch is located ateach of the intermediate floors from which an intending passenger maydesire t-o proceed in a down direction.

The elevator car A is provided with a door DP which is mounted to slideacross the passage through which passengers enter and leave the elevatorcar. The door is moved by means of a pivot 28A. The lever 28 is moved ina clockwise direction about a pivot by means of a door-close solenoid DCfor the purpose of closing the passage and is moved in acounterclockwise movement about its passage to open the door by means-of a dooropen solenoid DO.

When the door is open an object-detecting device is effective. Thisdevice preferably includes a signal or energy which is projected acrossthe passage through which passengers enter and leave the elevator car.This signal may be of any type which can be modified by the movement ofa passenger through the passage and in which the modification producedby such movement may bel detected. For example, the signal may be in theform of infrared radiant energy or ultra-violet radiant energy. As afurther exa-mple, supersonic energy may be projected across the passage.However, it will be assumed that the energy is in the form -of visiblelight which is produced by a lamp LA1 mounted on the edge of the doorwhich is the leading edge during a closing movement of the door. Thelight is in the form of a beam which is focused in any suitable manneron a suitable detector such as a photocell PC1. The output of thephotocell may be amplified by means of an amplifier AM1 which issupplied with electrical energy from a suitable source and the output ofthe amplifier is applied to a relay PR1. The relay PRl may be designedto be picked up as long as the photocell PCl receives the beam ofradiant energy. Detectors of this type are well known in the art.Examples of such detectors may be found in the Kinnard et al. Patent1,822,152 and in the Ellis, Jr. Patent 1,947,079.

Although a single beam may suffice, in Some cases it is generallydesirable to employ a plurality of beams. Such beams may be produced byinterposing suitable reectors between the lamp LAI. and the photocellPCI to reect a beam across the passage several times before it reachesthe photocell. However, for present purposes, it will be assumed thatseparate lamps and photocells are employed for each of the beams. Thus,in Fig. lA, a second lamp LAZ is provided for projecting energy towardsa photocell PC2 which is associated with an amplifier AMZ and a relayPRZ.

In the embodiment thus far described, the lamp LAl is mounted on oneedge of the door DP. If desired, a lamp and a photocell may be placed inany positions wherein the beam between the lamp and photocell isinterruptedV by the entry of load into the elevator car or the departureof load from the elevator car. Thus the beam may be located between thecar and hoistway doors or it may be adjacent the hoistway door. A beampositioned about twelve inches above the floor has been found suitable.

In Fig. lA, a hoistway door DPH is provided which is coupled to the doorDP for movement therewith when the elevator car'is stopped at a floor.It will be understood that a separate hoistway door DPH is provided foreach of the floors served by the elevator car. The coupling of the twodoors may be effected in a conventional manner as by a vane DPV which issecured to the door DP for reception in the slot of a slotted block DPBwhich is mounted on the hoistway door DPH.

The hoistway door DPH is moved to close and expose a hoistway passagethrough which load enters and leaves the elevator car. As shown in Fig;1A,the lamp LA2 is mounted on a hoistway wall or door jamb to projectradiant energy across the hoistway passage towards the photocell PC2which also is mounted on a hoistway wall. By inspection of Fig. 1A, itwill be observed that the radiant energy transmitted from the lamp LAZto the photocell PC2 is interrupted each time a passenger enters orleaves the elevator car.

If desired, the edge of the door DP which is the leading edge during adoor-closing movement may have an object-sensing device such as asafety-edge SE of conventional type. When such an edge reaches anobstruction, it opens switches SE1, SEZ and SES which may be em-V ployedin circuits to stop or reopen the door or for other purposes. Ifcenter-opening doors are employed, a separate safety edge may beprovided for the edge of each door which is a leading 'edge' duringclosing movement, In the present case, it will be assumed that thesecond safety edge SEA is located on the elevator car adjacent thephotocells PC1, PC2. The safety edge SEA operates switches SEA1 and SEAZfor three purposes hereinafter set forth.

The load in the elevator car is weighed in any suitable manner as by thedeflection of a spring-mounted platform PL. Loads in excess of say 80percent of rated capacity open the normally-closed load weighing switchLW, and close a normally-open load weighing switch LWL Figure 2 Fig. 2shows circuits for the driving motor, the brake, the speed relay V, theup switch U, the down switch D, the car-running relay M, the holdingrelay G, the slowdown inductor relay E, the stopping inductor relay F,the up-preference relay W, the down-preference relay X, the timing relayT, the door relay 40, the door-control relay 45, the door-close relayDC, the door-open relay DO, the detector relay SR, the time-delay relaySRT and the expediter relay 300. Energy for the various circuits isderived from direct-current buses L| and L-.

Although various motor control circuits may be employed, it will beassumed that a control circuit of the variable-voltage type is employed.By inspection of Fig. 2, it will be noted that the armature 15A of thedriving motor 15 and the armature 29A of a direct-current generator 29,together with a series field winding 29B for the generator, areconnected in a series or loop circuit. The field winding 15B for thedriving motor 15 is connected directly across the buses L+ and L-.

:The magnitude and direction of energization of the driving motor 15 arecontrolled by the direction and magnitudhe of the energization of aseparately-excited field winding 29C provided for the generator 29. Itwill be understood that the armature 29A of the generator is rotated ata substantially constant rate by a suitable motor MO which may be apolyphase induction motor energized from a suitable source through aswitch MOS. Contacts MOSI are illustrated and are operated by the switchto closed position only when the motor MO is conditioned to run. Forpresent purposes, it will be assumed that operation of the switch MOS toclosed position also closes the contacts MOS1.

When the elevator car A is conditioned for up travel, the generatorfield winding 29C is connected across the buses L+, L- through makecontacts U2 and U3 of the up switch. When the elevator car A isconditioned for down travel, the generator field winding 29C isconnected across the buses through the make contacts D2 and D3 of thedown switch. The energizing circuit for the field winding may include aresistor R1 which is shunted by make contacts V1 of the speed relay V.By inspection of Fig. 2, it will be observed that the contacts U2, U3,D2 and D3 constitute in effect a reversing switch for controlling thedirection of energization of the field winding. The resistors R1 and thecontacts V1 are provided for controlling the magnitude of energizationof the field winding.

The speed relay V may be energized through either of two circuits. Oneof the circuits includes make contacts U4 of the up switch U, a limitswitch 30 which is normally closed and which is opened as the elevatorcar A nears the upper limit of its travel and the break contacts E1 ofthe slowdown inductor relay E. The other circuit is completed throughmake contacts D4 of the down switch D, mechanical limit switch 31 whichis normally closed and 'which is opened as the elevator car nears thelower limit of its travel in the down direction, and break contacts E2of the slowdown inductor relay.

As previously pointed out, the brake 17 normally is spring-biased intoengagement with the brake drum 16 andis released by energization of abrake coil 17B. The coil may be energized either through make contactsU1 of the up switch U or through make contacts D1 of the down switch D.

In order to energize the car-running relay M, certain safety devices 33must be in their safe conditions. Such safety devices may includeswitches which are open when the doors of the elevator car and theassociated hoistway doors are open, and which are closed when the doorsare closed to control the door relay 40. Such safety devices are wellknown in the art. The car-running relay M may be energized througheither of two circuits. One of the circuits includes the make contacts84)-1 of the starting relay 80, make contacts W1 of the up-preferencerelay W, break contacts F1 of the stopping-inductor relay,normally-closed contacts of a mechanical limit switch 34 which areopened when the car nears the upper limit of its travel, and the coil ofthe up switch U. When energized, the up switch U closes its makecontacts U to complete a holding circuit around the contacts 80-1 andW1.

The second circuit for energizing the car-running relay M includes thecontacts 80-1 of the starting relay, make contacts XI of thedown-preference relay X, break contacts F2 of the inductor stoppingrelay, normallyclosed contacts of a mechanical limit switch 35 which areopened as the elevator car nears the lower limit of its travel in thedown direction and the coil of the down switch D. When the down switch Dis energized, make contacts D5 are closed to provide a holding circuitaround the contacts 80-1 and X1.

Before the holding relay G and the inductor relays E and F can beenergized, make contacts M1 of the carrunning relay must be closed. Inaddition, any one set of make contacts J1 of the reversal relay, TTI ofthe car-call stopping relay, and K1 of the floor-call stopping relaymust be energized. A holding circuit around these contacts -isestablished upon closure of the make contacts G1. Energization of theinductor stopping relay F further requires closure of the break contactsV2, of the speed relay.

If the break contacts J2 of the reversal relay are closed, theup-preference relay W is energized only if the elevator car is notoperating in the down direction (break contacts D6 are closed); theelevator car is not conditioned for down travel (break contacts X2 areclosed); and normally-closed contacts of a mechanical limit switch 36are closed. The mechanical limit switch 36 is opened as the elevator carreaches its upper limit of travel. Make contacts M7 of the running relayshunt the contacts J2.

Energization of the down-preference relay X requires closure of thebreak contacts U6 of the up switch, closure of the break contacts W2 ofthe up preference relay, and closure of the normally-closed contacts ofa mechanical limit Vswitch 37. The mechanical limit switch 37 is openwhen the elevator car A is adjacent the rst or dispatching floor.

The doors for the elevator car A are controlled by a 'door-'controlrelay 45. For this relay to be initially energized, and assuming thatthe manual switches 64 and are open, the break contacts N1 and TN1 mustbe closed to indicate that the elevator car is not being loaded at aterminalfioor. Break contacts 70HT2 must be closed to indicate thatnon-interference time allowed for a corridor or floor call has elapsedor the switch 64 must be closed. In addition, the break contacts 70T1must be closed to indicate that the general non-interference time hasexpired. The switch SE1 must be closed to indicate that the safety edgeSE of the door is not deiiected. The make contacts SR1 must be closed toindicate that no object is positioned in the closing path of the door.Finally, the break contacts 70-1 must be closed to indicate that anauxiliary or shortened non-interference time has expired. When the relay45 picks up, it closes make contacts 45-1 to partially complete aholding circuit for the relay.

If the switch 90 is closed, the energization of the relay 45 is furthercontrolled by two circuits, one containing the switch MOSl and makecontacts 45-4. The remaining circuit contains a cam-operated switch 68which is open only when the elevator car is at the lower terminal floor,a switch TS1 which is open only when the elevator car is assigned fordown peak operation and break contacts NUI of a timing relay.

Should the safety-edge contacts SE1 be held open for an unreasonablylong time (a door-hold button could be provided to control the relay 45in a similar manner) or should the beams of light across the doorway beinterrupted for an unreasonably long time, the break contacts NUAl closeto establish with the contacts TN1 and N1 an energizing circuit for therelay r45.

The door-control relay 45 controls the energization of the door-closesolenoid DC and the door-open solenoid DO. If the contacts 45--2 of thedoor-control relay are closed, and the break contacts 40-2 are closed,the solenoid DC is energized. The contacts 40,'-2 are closed when thedoor of the elevator car A or an associated hoistway door is away fromits closed condition. If a manual switch 64A is open the energization ofthe solenoid DC also is controlled by the contacts SE3 and SEA2 inparallel.

If the door-control relay 45 is dropped out, the make contacts 45-3 areclosed to complete with the switch 38 an energizing circuit for thedoor-open solenoid DO. The switch 38 is a limit switch which is normallyclosed and which is opened as the `door reaches its fully-open position.

The timing relay 70T is connected for energization by make contacts M5of the car-running relay. The energizing circuit is completed throughbreak contacts 300-1 of an expediter relay. It will be noted that aresistor R2 is connected across the timing relay 70T and the contacts300-1. If the timing relay is energized and the contacts M5 thereafteropen, the resistor R2 delays the dropout of the timing relay 70T for asuitable non-interference time, such as 5 seconds. If the contacts 300-1open, the relay 70T drops out promptly.

The detector relay SR is controlled by the make contacts PRI-1 andPRZ-l. These contacts are closed respectively as long as the photocellsPCI and PC2 (Fig. l) are illuminated by their respective radiant energybeams. The contacts may be bypassed by operation of a manual switch 62.

Break contacts SR2 and SRS of the relay SR respectively control theenergization of the time delay relay SRT and the expediter relay 300.The time delay relay SRT may have a time delay in dropout of the orderof one-half second when shunted by the entire resistor RES. lf a portionof the resistor is shuntedthrough the make contacts L3, the breakcontacts 50A1 and the manuallyoperated switch MS, the time delay indropout of the relay SRT is increased to alarger value such as two See-.0nds. The contacts L3 are,closed only Whentheelevator car A is adjacentthe first ornstrveet floor.H The contacts 50A1 are closed only when acar call is registered.'- For the present it will be assumed that theswitch MS is open.

The expediter relay 300 also may be energized by closure of contacts 51.These contacts may be arranged to close whenever a car call isregistered in the elevator car A for the purpose of expediting departureof the elevator car from a tloor at which it is stopped. For presentpurposes it will be assumed that the contacts 51 represent a push buttonwhich is located in the elevatorcar A and which is operated to expeditedeparture ofthe elevator car from a oor.

Although the lamps LA1 and LA2 of Fig. 1 may be continuouslyilluminated, they are illustrated in Fig. 2 as illuminated through breakcontacts M6 of the caryrunning relay M. k y

The car call detector relay 50A is energized through `contacts ZCY toSCY of the car pull push buttons. When any of the push buttons isoperated the associated contacts are opened. When no car call isregistered all contacts ZCY to SCY are closed.

F igure 3 Fig. 3 illustrates additional circuits for controlling dooroperation and circuits for energizing the car-call stopping relay TT andthe floor-call stopping relay K.

If make contacts K2 of the hoor-call stopping relay and the breakcontacts I3 of the reversal relay are both closed, the timing relay'70HT is energized and picked up. This relay has a time delay in dropoutdetermined by a resistor R3 which may be of the order of two seconds toestablish a shortened non-interference time under certain conditions. Ifa different time is desired at a certain floor a mechanical switch 69may be operated at such floor to modify the dropout time. In the presentcase the switch closes to shunt a portion of the timing resistor R3 inorder to increase the dropout time to `say three seconds.

Make contacts 70HT1 and SRTI in parallel control the energization of anauxiliary relay 70.

Make contacts SR4 control the energization ofa timing relay NU. Thisrelay has a time delay in dropout (determined by a resistor R4) whichmay be of the order of four seconds.

Make contacts SRS of the detector relay SR and the contacts SEZ operatedby the safety edgeSE control in part the energization of a timing relayNUA which has a time delay in dropout of say twelve seconds asdetermined by a resistor R5. If the relay NUA is dropped out, openingofmake contacts LWAl drops out the relay promptly.

The timing relay LWA is energized through any of four paths. One pathcontains the break contacts LW of the load weighing switch LW. A secondpath contains break contacts of a switch 68A which is closed only whenthe elevator car is at the bottom terminal oor and contacts T53 whichare closed only during down peak periods. The third path has contacts ofa mechanical switch 68B which is closed only when the elevator car isaway from the terminal floors and contacts TS4 which are closed onlyduring up peak periods. The fourth path contains a limit switch 33Awhich is open only when the door is open.

The car-call push buttons 2c to 5c normally are biased into their openpositions against two sets of back contacts 26x to 50x and 2cy to Scy.Each of the push buttons is provided with a holdingcoil 2cc to 5cc,which is effective for holding the associated push button in its openated condition following a manual operation of such push button. To thisend, the push buttons may be made of magnetic material. Suchconstruction of the push buttons is well known inthe art.

Each of the push buttons 2c to 5c has front contacts controlling theconnection of contact segments to the bus L+. Thus, when operated, thepush button 2c connects the contact segment h1 to the bus L+.v Whenoperated,

the push button 2c connects the contact segments a2 and h2 to the busL+. The push buttons 3c and 4c similarly connect contact segments forthe third and fourth floors to the bus L+. Inasmuch as the elevator caris assumed to stop at the iifth oor or upper terminal floor at all timesduring up travel, the contact segment a5 is permanently connected to thebus L+. Similarly, during down travel, the elevator car A always stopswhen it reaches the iirst oor, and the contact segment h1 for the firstfloor is permanently connected to the bus L+.

It will be understood that the contact segments a2 to a5 are arranged ina row on the oor selector 19 of Fig. 1 and are successively engaged by abrush 23 as the elevator car moves from its lower limit to its upperlimit of travel. In a similar manner, the contact segments h4 to h1 arearranged in a row in the order of the oors for successive engagement bya brush 40a as the elevator car moves from the upper terminal to itslower limit of travel.

- During up travel of the elevator car A, the car-call stopping relay TTis connected between the brush 23 and the bus L- through make contactsW3 of the up-preference relay and make contacts M3 of the car-runningrelay. Consequently, when the brush 23 reaches one of the contactsegments a2 to a5 which is connected to the bus L+., the car-callstopping relay TT is connected for energization across the buses L+ andL- for the purpose of stopping the elevator car at the next floorreached by the car. As the elevator car stops, the brush 23 preferablypasses slightly beyond the associated contact segment.

When the elevator car A is conditioned for down travel, the car-callstopping relay TT is connected between the brush 40a and the bus L-through the make contacts X3 of the down-preference relay and the makecontacts M3 of the car-running relay. Consequently, when the brush 40areaches one of the contact segments h4 to hl which is connected to thebus L+, the car-call stopping relay TT is energized to initiate astopping operation of the elevator car at the next floor reached by thecar. As the elevator car stops, the brush 40a preferably passes slightlybeyond the associated contact segment.

The coils Zac to 5cc are connected in series for energization eitherthrough make contacts W4 of the 11p-preference relay or make contacts X4of the down-preference relay. When the elevator car reverses itsdirection of travel, the make contacts W4 and X4 both are momentarilyopened todeenergize the associated holding coils for the purpose ofresetting the car-call push buttons.

Each of the push buttons 2c to 5c when operated opens a set of contacts2cy to Scy, respectively. These contacts control the car-call detectorrelay SGA (Fig. 2).

Each of the car-call buttons when operated also opens an auxiliary setof normally-closed contacts 20x, 3cr and 4cx respectively. These areemployed in a high call circuit which will be discussed below. A set ofcontacts 50x and a holding coil 5cc also are provided for the iifth oor.

When the down floor-call push button 2D is operated, the down floor-callstoring relay 2DR is connected therethrough across the buses L+ and L+for energization. Upon energization, the relay closes its make contactsZDRl to establish a holding circuit around the push button. The contactsegment f2 now is connected (and corresponding contact segments for theremaining elevator cars are connected) through the contacts 2DR1 to thebus L+. The contact segments f4 and f3 similarly are connected to thebus L+ by operation of the down floorcall push buttons 4D and 3D. Thecontact segments f4, f3 and f2 for the fourth, third, and second oorsare positioned in a row on the floor selector 19 of Fig. l forsuccessive engagement by a brush 52 as the elevator car A moves from theupper terminal in a down direction.

The floor-call stopping relay K is connected between the bus L+ and thebrush SS through make contacts X5 of the down-preference relay.Consequently, if the elecoil.

Aand 2DR has an operating coil and a cancelling coil,

respectively, 4DRN, SDRN and ZDRN which is energized in opposition -tothe energization of the operating The cancelling coil ZDRN is connectedbetween a contact segment g2 (and similar contact segments BgZ etc. forthe other elevator cars) and the bus L+ through the make contacts ZDR.As the elevator car A reaches the second oor, the following energizingcircuit for the cancelling coil v is established:

L+, ZDRl, ZDRN, g2, 59,X6, M4, L-

kEnergizationfof the coil ZDRN opposes energization of the relay by theoperating coil and resets the relay. it will be understood that thecontact segments g4, g3 and g2 are arrangedin a row for successiveengagement by the brush 59 as the elevator car proceeds downwardly fromthe upper terminal door to control the energization of the cancellingVcoils iDlN, SDRN and ZDRN.

The down hoor-call storing relays all cooperate with the brushes 58 and59 in substantially the same manner to control the energization of thefloor-'call stopping relay during down travel of the elevator car.

VWhen the up floor-call push button 2U is operated, the up floor-callstoring relay ZUR is connected for energization therethrough acrossV thebuses L+ and L Upon operation, the relay closes its make contacts 2UR1to establish a holding circuit-around the push button 2U. As a result, acontact-segmentb2 is connected (and contact segments Bb2 etc. for theother elevator cars are connected) to the bus L+ through such makecontacts.

As the elevator car during up travel approaches the second door, thebrush 60 engages the contact segment b2 to establish the followingenergizing circuit for the oor-call stopping relay:

L+, ZURI, b2, 60, W5, K, L-

This conditions the elevator to stop at the second oor. As the elevatorcar stops at the second floor, a brush 61 engages the contact segment c2to establish the following circuit for the cancelling coil of thestoring relay ZUR:

` L+, 2UR1, ZURN, c2, 61, W6, M4, L-

Such energization of thecancelling coil results in resetting of thestoring relay which has its main coil acting in opposition to thecancelling coil. The up floor-cal push buttons 3U and 4U similarlycontrol the associated storing relays and contact segments. It will beunderstood that the contact segments c2, vc3 and c4, and contactsegments b2, '23 and b4 are arranged in rows on the floor selector'forengagement successively by the brushes 61 and 60, as the elevator car Aproceeds upwardly.

. Figure 4 In Fig. 4 a starting relay 80, a dispatching device whichnormally controls the lower terminal dispatching of the elevator carsemployed in the system, and a reversal relay J are illustrated.

The starting relay S can be energized only if the timing relay 7?? isdeenergized and dropped out to close its break contacts 70T2. Ifadditional non-interference time is allowed for a corridor or oor call,the manual switch 65 is open and break contacts 70HT3 of the timingrelay also must be closed to permit energization of the relay 80. Whenthe elevator car is positioned at the lower dispatching iloor, theenergizing circuit for the starting relay normally is completed throughthe make contacts S1 of an auxiliary starting relay. At theupperterminal or dispatching floor, make contacts UTSl may operate in amanner similar to the operation of the contacts S1 for 14 the lowerdispatching oor to start the elevator car from the upper terminal oor.Between the dispatching floors, the make contacts Sl are shunted by thecontacts of a mechanical switch 63. This switch is cam operated to openwhen the elevator car is adjacent the upper terminal or dispatchingtloor and the lower dispatching floor. For all other positions of theelevator car A, the switch 63 is closed.

The selection and timing mechanism include as one component a motor 71which operates substantially at constant speed. This motor may be of anysuitable type, but for present purposes it will be assumed that thevmotor is a squirrel-cage alternating-current motor which is energizedfrom a suitable source of alternating current. The motor 71 is connectedthrough a spring-released electromagnetically-applied clutch 72 to a cam73 having a protuberance for successively operating mechanical switchesY, BY, CY and DY which are associated with the respective elevator cars.The electromagnetic clutch can be energized only if one or more elevatorcars are located at the dispatching Hoor which is assumed to be thefirst floor (one or more of the contacts L1, BLl, CLI, DLI are closed),and if no elevator car has been selected as the next car to leave thedispatching floor (break contacts N2, BN2, CN2 and DNZ all are closed).

The motor 71 also may be coupled through a springreleasedelectromagnetically applied clutch 74 to a cam 75 which is biasedtowards a predetermined position by a spring 76. The cam 75, whencoupled to the motor 71, is rotated against the bias of the spring toclose normally open contacts 77 a predetermined time after the cam 75 iscoupled to the rnotor 71. The clutch 74 can be electrically energizedonly if no elevator car is being started (break contacts S2, BSZ, CS2and DS2 are closed), and if the break contacts 1S1 of the holding relay1S are closed. The holding relay 1S is energized upon closure of thecontacts 77 to close its make contacts 1S2 for the purpose ofestablishing a holding circuit around the contacts 77.

The presence of an elevator car at the dispatching floor is determinedby the energization of a car-position relay for each of the elevatorcars. Thus, a car-position relay L for the elevator car A is energizedwhen the brush 24 engages the contact segment e1.

The brush 24 is operated by the floor selector for the elevator car A toengage the contact segment e1 when the elevator car is at thedispatching floor.

If the elevator car A is at the dispatching floor (make contacts L2 areclosed, if it has been selected as the next car to leave the dispatchingfloor (switch Y is closed), and if it is not being started (breakcontacts S3 are closed), the loading relay N for the elevator car A isenergized. The loading relay may be employed in a conventional way topermit loading of the elevator car A. For example, the loading relaywhen energized may operate a loading signal, such as a lamp, whichindicates that passengers may enter the elevator car. Conveniently, theloading relay N when energized opens the normallyclosed doors of theelevator car A to permit entry of passengers into the elevator car.

After the expiration of a time sufcient for cam 75 to close the contacts77 and energize the relay 1S, the make contacts 1S3 close to completethe following circuit:

L+, LZ, S, N3, 1S3, L-

The relay S when energized closes its make contacts S4 to establish aholding circuit around the contacts N3 and 1S3, and starts the elevatorcar A from the dispatching floor.

If the elevator car is loaded before expiration of the interval measuredby the relay 1S it may be advisable to expedite departure of the car. Tothis end a manual switch 99 may be closed to connect the relay 2S forenergization through any of four parallel circuits, one for each of theelevator cars. The circuit for the elevator car A includes breakcontacts 70T3 of the non-interference relay, make contacts N4 of theloading relay and a switch LW1 which is closed only when the load in theelevator car exceeds say 80 percent of rated capacity. Thus if theelevator car A is selected as the next car to leave the terminal floor(contacts N4 are closed), if the non-interference time has expired(contacts 7T3 are closed) and if the elevator car is fully loaded(switch LW1 is closed) the relay 2S picks up and closes its contacts2S1. Since the contact 2S1 shunt the contacts 1S3, prior closure of theformer contacts expedites dispatch of the elevator car.

Fig. 4 also discloses a reversal relay I which is connected between abrush 66 and the bus L+ through a manually-operated switch 67 and makecontact W7 of the up-preference relay. The brush 66 and an associatedrow of contact segments k2, k3 and k4 are included in the licor selectorof Fig. 1. The contact segments are associated with a call circuit whichincludes break contacts of the call registering relays and the contacts3CX, 4CX and SCX associated with the carcall push buttons. By tracingthis circuit in Fig. 4 it will be noted that the bus L+ is connected tothe contact segment h2 through the following circuit:

3UR2, 3DR2, 3CX, 2UR2, k2

(A down floor call registering relay is not illustrated in Fig. 3 forthe fifth ioor, but it will be understood that the break contacts 5DR2of Fig. 4 are operated by a push button for the fifth floor in the samemanner by which break contacts 4DR2 are operated by its push button forthe fourth floor). Consequently, contacts of all call registering relaysor car-call push buttons which when operated require car travel abovethe second floor are located between the contact circuit segments k2 forthe second iioor and the bus L+.

The contact segment k3 is connected to the call circuit between thecontacts 3UR2 and 3DR2. Consequently, contacts of all call registeringrelaysor car-call push buttons requiring travel of the elevator carabove the third floor are located between the contact segment k3 for thethird oor and the bus L+. In an analogous manner, the contact segment K4for the fourth floor is connected to the call circuit at a point betweenthe contacts 4UR2 and 4DR2. Such call circuits are well known in theart.

Operation In order to explain the over-all operation of the elevatorsystem, it will be assumed first that the elevator cars are at the firstor dispatching floor when the system initially is energized. The carsare conditioned for operation in the up direction. For example, theswitches MOS and MOSl are closed and the elevator car A has itsup-preference relay W energized. Consequently, make contacts W1, W3, W4,W5, W6, W7 of the relay are closed, whereas break contacts W2 of therelay are open.

The switches 90 (Fig. 2), 63A (Fig. 3) and 67 (Fig. 4) are assumed to beopen. Since the cars are at the first floor, the switch 63 also is open.The timing re'lay 70T is assumed to have timed out. and 40 are picked upand the elevator car doors are closed. Switches 64A and 68A are closedand switch 68B is open.

The motor 71 (Fig. 4) is energized to rotate at a substantially constantrate.

inasmuch as the elevator cars are assumed to be at the dispatchingfloor, the car-position relays L, etc. are energized. n A As a result ofits energization, the car-position relay L lcloses its make conta-cts L2to prepare certain circuits for subsequent energization. In addition,the make contacts The relays SR, 45

L1 close toV complete the following circuit for the clutch 72.

The clutch now couples the motor 71 to the cam 73 for the purpose ofsuccessively closing and opening the associated mechanical switches. Itwill be assumed that the first switch reached by the cam is the switch Yfor the elevator car A. Closure of this switch completes the followingenergizing circuit for the loading relay of the elevator car A:

The loading relay N upon energization initiates opening ofnormally-closed doors of the elevator car A to permit intendingpassengers on the dispatching floor to enter the elevator car. Suchopening is effected by opening 'of contacts N1 (Fig. 2) to deenergizethe door-control relay 45. This relay opens its contacts 45-1 and 45-2without immediate effect on system operation. However, closure ofcontacts 45-3 energizes the solenoid DO to open the doors. In opening,the door opens its set of contacts 33 to deenergize the door relay 40which opens its -contacts 40-1 and closes its contacts 40--2 withoutimmediate effect on system operation. When it kreaches open position,the door opens limit switch 38 t0 deenergize the solenoid DO.

Opening of the break contacts N2 (Fig. 4) deenergizes the clutch 72.Consequently, the cam 73 is uncoupled from the motor 71. Finally, themake contacts N3 close `to prepare the starting relay S for subsequentenergization.

When the system was placed in operation, the clutch 74 was energizedthrough the circuit:

L+, 1s1, 74, sz, Bsz, cs2, Dsz, L-

As a result lof its coupling to the motor 71T, the cam 75 rotatesaga-inst the bias of its spring 76 until at the expiration of the timeinterval allowed lfor loading elevator cars the contacts 77 close.Closure of these contacts completes the following circuit:

L+, 1S, 77, S2, BSZ, CS2, DSZ, L-

The energized relay 1S closes its make contacts 1S2 to establish aholding circuit Iaround the contacts 77. The break contacts 1S1 open todeenergize the clutch 74, and the spring 76 now rotates the cam to itsstarting position. Also, the make contacts 183 close to energize theauxiliary starting relay S through the following circuit:

Energization of the auxiliary starting relay S closes the make contactsS4 to establish a holding circuit around the contacts N3 and 1S3. Breakcontacts S3 open to `deenergize the loading relay N. Break contacts S2open, and this opening causes relay 1S to drop out. This has noimmediate effect on the system operation.

The loading relay when deenergized opens its make contacts N3 withoutimmediate eiect on the operation of the system. In addition, breakcontacts N2 close to prepare the clutch 72 for subsequent energization.

The deenergization of the loading relay further closes break contacts N1(Fig. 2) to complete with the contacts 704-1, SR1, 70T1 and TN1 anenergizing circuit for the door-control relay 45. The latter relaycloses its make contacts 45-1 and opens its break contacts 45--3 withoutimmediate effect on system operation. However, closure of make contacts45-2 completes with the contacts 40-2 an energizing circuit for thedoorclose solenoid DC, and the door now Starts to close. 4If the switch62 is open and a passenger is in the closing path of the door, helinterrupts one of the beams of radiant energy and one of the sets ofcontacts PRI-1 or PR2+2 opens to deenergize the detector relay SR.

This relay then opens its rn-ake contacts SR1 to deenervgize thedoor-control relay vtacts 45-2 to deenergize the door-close solenoid and'closes its contacts 45-3 to energize the door-open sole- 45. The latteropens itsconnoid for the purpose of reopening a partly-closed door.

nThe detector relay also closes its break contacts SR2 and "SRS toenergize the relays SRT and 300. The energization of the relay 300 hasno effect -at this time on the operation of the system but theenergizat-ion of the relay SRT closes make contacts SRTI to pick up thetiming relay 70 (Fig. 3). This relay opens its break contacts '70-1.After the passenger clears the door closing path, the detector relay SRpicks up to close its make contacts SR1, and `open its break contactsSR2 and SR3. The resultant dropout 4of the relay 300 has no effect atthis 'time on the system operation. However, the opening of contacts SR2starts a timing out operation of the relay SRT. .After the expiration ofits time delay, such as onehalf second, the relay SRT drops out to openits con- .tactsSRTl and such opening drops out relay 70. The Yrelay 70closes its break contacts 70--1 to complete `a circuit for the relay 45.

'The Operations of relays NU, NUA and LWA will be discussed below.

In some cases, it is desirable to prevent a reopening sof the door bythe relay SR. In such a case, the manuallyfoperated switch 90 may beclosed to connect make contacts 45-4 of the door-control relay and theswitch MOSl -around the contacts SR1 and 70-1. When the door-controlrelay picks up, the resulting closure of its contacts 45-'4 assures doorclosure despite subsequent dropout of the relay SR, provided that theswitch MOSl is closed to indicate that the motor generator set isrunning.

, For 'the following discussion, the switch 90 is considered to be open.Even with the switch 90 closed, if the door actually encounters aperson, the safety edge would open the switch SE1 to deenergize therelay 45 and reopen the door.

It will be assumed however that no person is in the closing path andthat the door closes. Upon closing, the door closes its switch 33 tocomplete an energizing circuit for 'the door relay 40 which closes itsmake contacts 40-1 and opens its break contacts 40-2 to deenergize thedoor-close solenoid DC.

Turning now to Fig. 4, it will be noted that closure i of the makecontacts S1 results from energization of the auxiliary starting relay S.Inasmuch as the elevator car A is assumed to have remained at thedispatching iloor for 'agtime suicient to permit closure of the breakcontacts 70T2, an energizing circuit now is complete for the mainstarting relay 80. Switch 65 is assumed to be closed.

The previously mentioned closure of contacts 40-1 of the door relay(Fig. 2) coupled with closure of the make contacts 80-1 of the startingrelay completes the following circuit for the up switch and thecar-running relay:

, L+, 80-1, W1, F1, 34, U, M, 40-1, L-

The energized up switch U closes its make contact U1 to release thebrake 17, and contacts U2 and U3 close to energize the generator eldwinding 29C with proper polarity for up travel of the elevator car. Makecontacts U4 close to complete through the limit switch 30 and thecontacts E1 an energizing circuit for the speed relay V. The'speed relaycloses its make contact V1 to shunt the resistor R1 and condition theelevator car A for full speed operation in the up direction. Also, thespeed relay opens its break contacts V2 to prevent energizationtherethrough of the stopping nductor relay F.

Returning to the up switch U, it will be noted that closure of the makecontacts U5 establishes a holding circuit karound the contacts 80-1 andW1. Opening of the break contacts U6 prevents energization therethroughof. the down preference relay. The elevator car Av now is in conditionfor full speed operation in the up direction and departs from thedispatching iloor.

.It will be recalled that the car-running relay M was 18 energized withthe up switch U. The car-running relay closed its make contacts M1, M3,M4 and M7 (Fig. 3) without immediate eltect on the operation of thesystem. However, closure of the make contacts M2 (Fig. 2) completes withthe contacts 45-1 and N1 a holding circuit for the door-control relay45. Opening of break contacts M6 deenergizes the lamps LA1 and LA'2.Closure of the make contacts M5 energizes the .timing relay 7 0T. Thisrelay opens its break contacts 70T2 (Fig. 4) which causes the startingrelay to become deenergized. Opening of break contacts 70T1 (Fig. 2)does not immediately affect system operation.

It will be assumed now that the passenger in the elevator car operatesthe car-call push button 3c (Fig. 3) to register a car call -for thethird oor. Such operation opens the contacts 36x without immediateeffect kon the system and connects the contact segments a3 and h3 to thebus L-|. As the elevator car nears the third iloor, the brush 23 engagesthe contact segment a3 to complete the following circuit for thecar-call stopping relay TT:

The car-'call stopping relay now closes its make contacts TTI (Fig. V2)to energize the holding relay G and the slowdown nductor relay E throughthe closed contacts M1. Energization of the holding relay G completesthrough the make contacts G1 a holding circuit around the contacts TTI.

When the elevator car A in its upward travel reaches the nductor plateUEP (Fig. `1) for the third floor, the break contacts E1 are opened todeenergize the speed relay V (Fig. 2). The speed relay opens its breakcontacts V1 to introduce the resistor R1 in series with the generatoriield winding 29C. The resultant reduction in eld current slows theelevator car to a landing speed. In addition, the speed relay V closesits break contacts V2 to complete through the contacts G1 and M1 anenergizing circuit for the stopping nductor relay F.

Shortly before the elevator car A in its continued upward movement atthe landing speed reaches the third floor, the nductor plate UFP for thethird iloor is adjacent the stopping nductor relay and completes amagnetic circuit which results in opening of the contacts F1. Opening ofthe contacts F1 (Fig. 2) deenergizes the up switch U and the car-runningrelay M. p

The up switch U opens its make contacts U1 to deenergize the brake 17,and the brake is promptly forced against the brake drum 16 by itsassociated spring. Conf tacts U2 and U3 open to deenergize the generatorfield winding 29C. Consequently, the elevator car A stops accurately atthe third floor. Opening of the make contacts U4 and U5 and closure ofthe break contacts U6 have no immediate eiect on the operation of thesystem. As the elevator car comes to a stop the brush 23 may pass thecontactpsegment for a slight distance t deenergize the relay TI.

The previously-mentioned deenergization of the carrunning relay resultedin opening of the make contacts M1 to deenergize the nductor relays Eand F and the holding relay G. The holding relay G opened its makecontacts G1 without immediately affecting the operation' of the system.

The car-running relay also opened its make contacts M5 to starttiming-out operation of the timing relay 70T. Contacts M5 preferablyopen with a slight time delay to` assure prior closure of contacts300-1. This relay 70T has a time delay in drop out sufficient to permitdis= charge of passengers or entry of passengers into the ele-I vatorcar A. For example, a time delay of ve seconds may be employed. Openingof the make contacts M3 and closure of the break contacts M4 have noimmediate effect on the operation of the system. Closure of contacts M6illuminates the lamps LAI and LA2, and these illuminate their associatedphotocells to close' contacts PRll and P R2-1 which pick up relay SR.The pick up of relay SR` and the resulting deenergization of relays SRTand push button 3U (Fig. 3).

sdraio i9 300 have no immediate effect on the operation. However, theArelay SRT starts to time out.

Opening of the make contacts M2 deenergizes the door control relay 45and this relay opens its make contacts 45-1 and 45--2 without immediateeffect on system operation. However, closure of break contacts 45-3completes with the switch 38 a circuit for the door-open solenoid DO andthe door now opens. 1n opening, the door opens its switch 33 todeenergize the door relay 40 without immediate effect on systemoperation.

Let it be assumed that instead of a car call, an up floor call wasregistered for the third floor by operation of the Such operationenergizes the up oor call storing relay 3UR which closes its makecontacts 3UR1 to establish a holding circuit around the push button. Thecontacts 3UR1 also serve to connect the contact segment b3 andcorresponding contact segments for the remaining elevator cars of thesystem to the bus L|-. Opening of contacts 3UR2 and 3UR3 does not affectthe operation of the system at this time.

As the elevator car approaches the third floor, the brush 60 engages thecontact segment b3 to energize the floorcall stopping relay K throughthe following circuit:

Upon energization, the floor call stopping relay closes its makecontacts K1 (Fig. 2) to energize through the contacts M1 the holdingrelay G, the slowdown inductor relay E and the stopping inductor relayF. These relays operate in the same manner previously discussed to stopthe elevator car accurately at the third floor. Contacts K2 of the floorcall stopping relay also close to complete with the contacts J3 anenergizing circuit for the relay 70HT. The latter relay 70HT closes itsmake contacts 70HT1 and opens break contacts 70HT2 and 70HT3 withoutimmediately effecting the operation of the system.

As the elevator car A slows down to stop at the third floor, the brush61 engages the contact segment c3 to complete the following cancellingcircuit:

L+, 3UR1, 3URN, c3, 61, W6, M4, L-

It will be recalled that the break contacts M4 close as the elevator carstops at the third tloor. As a result of its energization, thecancelling coil 3URN resets the up floor-call storing relay for thethird oor. Such reset is accompanied by deenergization of the floor-callstopping relay K which opens its make contacts K1 without affectingsystem operation. However, the opening of the make contacts K2 starts atiming out operation of the relay Referring to Fig. 4, is will berecalled that the mechanical switch 63 is open only at thedispatching-floor andthe upper-terminal floor positions of the elevatorcar. Since the elevator car is now at the third floor, the switch 63 isclosed. Consequently, as soon as the timing relay 70T drops out, thebreak contacts '70[2 close to complete an energizing circuit for thestarting relay 80. This operates in the manner previously discussed tostart the elevator car upwardly. In this way, the elevator car Acontinues to the upper terminal fioor, answering all registered carcalls and all registered up floor calls during its upward trip.

As previously pointed out, the drop out of the timing relay 70T providesnon-interference time which may be of the order of 5 seconds. ifdesired, a longer non-interference time may be provided for a stop madein response to a corridor or floor stop. For example, assume that theswitches 64 (Fig. 2) and 65 (Fig. 4) are open and that the relay 70HThas a delay in drop out of say six seconds. Under such circumstances,the relay 45 (Fig. 2) cannot be energized to close the door and therelay 80 (Fig. 3) cannot be energized to permit starting of the caruntil a non-interference time of six seconds has elapsed to permitclosure of contacts 70HT2 and 70HT3. It willpbe assumed, however, thatthe switches 64 and 65 are closed.

lf a passenger leaves the elevator car at the third floor promptly, say,in 1 second, it follows that a substantial and unnecessary delay in thedeparture of the elevator car would be imposed if the relay 70T isallowed to complete its normal timing interval before the car departsfrom the third floor.

In the present case, the departure of the elevator car isexpedited to anextent dependent on whether the elevator car is answering a car call ora floor call. By reference to Fig. 1, it will be noted that when the carstops for a car call and the passenger leaves the elevator car at thethird floor, he temporarily interrupts the beams of radiant energydirected towards the photocells PCI and PC2. Such temporary interruptiontemporarily interrupts and drops out the relays PR1 and PRZ.

Referring to Fig. l and Fig. 2, it will be noted that the drop out ofthe relays PRI and PRZ opens make contacts PRI-1 and PR2-1 to deenergizethe detector relay SR. The detector relay opens its make contacts SR1 toprevent energization therethrough of the door-control relay 45 as longas the passenger stands in the closing path of the door. In addition,break contacts SR2 and SRS close to energize the time delay relay SRTand the expediter relay 300. Energization of the time delay relay SRTresults in closing of the make contacts SRT1 and pick up of the relay 70without immediately affecting the loperation of the system. The relay 70opens its break contacts '7d-1. The expediter relay 300 opens its breakcontacts 309-1 to instantly drop out the timing relay 70T. Since thetiming relay is now droppedout, it closes its break contacts 70T1.However, since the contacts SR1 and 70--1 are open, the door-controlrelay 45 cannot be energized. In addition, break contacts 70T2 (Fig. 4)close to complete with the switch 63 an energizing circuit for the mainstarting relay 80. The main starting relay 89 closes its make contacts80-1 (Fig. 2) without immediate effect on the operation of the system.Contacts SR4 and SRS (Fig. 3) open to start timing out operations of therelays NU and NUA.

It will be assumed that the passenger passes promptly through thedoorway and that the beams of radiant energy are promptly reapplied totheir associated photocells. As a result of such reapplication, the makecontacts PRl-l and RRZ-1 reclose to energize the detector relay SR. Thisrelay opens its break contacts SRS .to deenergize the expediter relay.300, but such deenergization has no immediate effect on the operationof the system. Opening of the break contacts SR2 initiates a timing outoperation of the time delay relay SRT. Closure of the make contacts SR1has no immediate effect on the energization of the door controll relay45 for the reason that the contacts l0-1 are still open. Closure of makecontacts SR4 and SRS (Fig. 3) reenergizes the relays NU and NUA. v

Upon the expiration of the one-half second time delay in dropout of the-relay SRT, this relay drops out to open its make contacts SRT1. Theauxiliary relay 70 now closes its break 'contact 70-1 to complete theenergizing circuit for the door-control relay 45. This relay 45thereupon operates in the manner previously described to initiate adoor-closing operation of the door of the elevator car A and thestarting of the elevator car A from the third floor. It should be notedthat this operation may save several seconds of time in starting theelevator car from the third floor.

Should another passenger immediately follow the first passenger to leavethe elevator car at the third floor, the radiant energyy beams againwould be interrupted to deenergize the detector relay SR. This relaywould reclose its break contacts- SR2 to reenergize the time delay relaySRT. vSince the relay SRT has not yet dropped out, the reenergizationthereof occurs before the elevator car door starts to close and delaysreclosure of the door for the full time delay of the relay SRT. If alarger number of passengers follow each other out of the elcf 21 vatorcar A, it follows that the relay SRT is reset in re spense -toeach-.departure of a passenger. A similar operation results from thesuccessive entry of aplurality of passengers linto the elevator car.Following Ythe entry of the'last passenger, vthe relay 45 is operatedtoclose the `door and start rthe elevator car.

The effect of movementof avpassenger or an intending passengerout of orinto the elevator car located at the third oor now will be consideredfor 4the case in which theelevator car has stopped at the third'lloor inresponse to vthe oor call registered by operation of the push button 3U.It wil-lberecalled that if the elevator car A stopped at the third floorunder these conditions, the make contact K2 `(Fig. r3) closed toenergize Ithe timing relay 70HT and then reopened to start a timing outoperation of the relay. For present purposes, this relay may have adelay in drop out of the order of two seconds. When the relay 70HT wasenergized, it closed its contacts 70Hl`1 to .assist in maintainingenergized the auxiliary relay 70. It is assumed that the switch 64 isclosed to shunt the break contacts 70HT2.

1f no passenger enters or leaves the elevator car for a periodof twoseconds, the timing relay 70HT finally drops out to deenergize theauxiliary relay 70. The relay 70 closes rits break contacts 70-1 (Fig.2) but the door control relay 45 cannot yet be energized for the reasonthat the break contacts 70T1 of the timing relay 70T are still open.

`If the elevator car remains at the third oor for a total of lliveseconds without the entry of an intending passenger or departure of apassenger from within the elevator ca r, the timing relay 70T drops outto close its break ontacts 70T1 and '70T2 (Fig. 4*). This .operation ofthe timing relay initiates the closing of .the door and the starting ofthe elevator car from the third oor in the manner previously described.

Next let it be assumed that va passenger left the elevator c ar onesecond after the elevator car stopped at he third floor. vIt will berecalled that at this time the timing relays 70T and 70HT both arepicked up and both are timing out.

As the passenger passes through the doorway he temporarily interruptsthe beams f radiant energy directed @Werd the photocells PC1 and PC2-Consequently. the relays PRl and PRZ temporarily drop out to interruptmomentarily the energizing circuit Vfor the detector relay SR. TheVdetector relay SR momentarily vopens its make Contact SR1 withoutimmediate effect on the operation of the system. In addition, breakcontacts SR2 and SR3 close to energize the time delay relay SRT and theexpediter relay 300. Opening of the make contacts SR4 and SRS startstiming out operations of the relays NU and NUA- As a result of its dropout, the expediter relay 300 QPHS, its break contacts th-..1 to drop outinstantly the timing relay 70T. The resulting closure of the breakQlltaCts 70Tl is inellective for energizing door control relay 45 forthe reason that the break contacts 70-1 of .the auxiliary relay 70 arestill open. The closure of the break contaetSv'lQTZ (Fig. 4) completesan energizing circuit for the main starting relay 80. However, the mainstarting relay Cannot start the elevator car until the door closed.

The temporary energization; of the time delay relay results in anenergizing and timing out of this relay, inasmuch as this relay isassumed to have a delay in` drop out of the order of one-.half second.It finally drops out to open make contact SRT1. Such opening has noeffect on the system for the reason that the make contacts 70HT1 arestill closed.

Upon the expiration of two seconds following the stopping of theelevator car at'the third oor, the timing relay- 70HT drops out to openits make contacts 70HT1. This deenergizes the auxiliary relay 'l0 andresults in closure of the `break contacts 'itk-1 vto complete thefollowing circuit:

The door control relay 45 is now energized to initiate a closingoperation of the door andthe resultant 'starting of the elevator car bya sequence which will be clear from the foregoing discussion.

Let it be assumed next that just before the timing relay 70HT timed outa second passenger followed the rst passenger out of the elevator car.This resultedl in another temporary interruption of the 'beams ofradiant energy directed towards the photocells PC1 and PC2 and atemporary drop out of the relays'PRl and PR2. Consequently, the detectorrelay SR again is ltemporarily dropped out to open vits make contacts'SR1 momentarily and close its break contacts SRS momentarily toenergize the relay 300. Such operations have no immedi ate eifect on theperformance of this system. The temporary ,opening of the make contactsSR4 and SRS starts a timing out operation of the relays NU and NUA andthen reenergizes the relays.

It will be noted that the relay SR also temporarily energizes the timedelay relay SRT and this relay closests make contacts SRT1 just beforethe make contacts 70HT1. Consequently, even though the time period forthe timing relay 70HT has expired, the make contacts SRT1 maintain theenergization of the auxiliary relay 70 for vapproximately a half seco-ndto permit movement of ,other passengers through the doorway as required.It will be recalled that the door cannot be reclosed until the auxiliaryrelay 70 drops out to close its -break contacts 70-1. From thediscussion, it should be clear that as long as suc -cessive passengersfollow each other into or out of the elevator car within one-half secondintervals, the door of the elevator car remains open` to permit suchmovement of the passengers. One-half second after the departure of thelast passenger, the contacts SRT1 open to drop out the auxiliary relay70 and permit closure of the elevator car door.

In order to make the relay NU effective for controlling the operation ofthe system, the manual switch maybe closed. Such closure connects thebreak contacts NUI of the timing relay NU and contacts of aswitch TS1across the contacts SR1 and 70-1.

If a passenger attempts to delay closure of the elevator car door bystanding in the path of the beams of radiant energy directed towardsphotocells PC1 and PC2, he also maintains open the make contacts SR4 topermit a timing out operation of the timing relay NU. Upon theexpiration of its time delay, which may be of the order of four seconds,this relay closes its break contacts to complete with the switch TS1 orthe switch 68 an energizing circuit for the door controlled relay 45.Under these circumstances, the door promptly starts to close. If thedoor is provided with a safety edge and the safety edge encounters thepassenger, the switch SE1 opens and initiates a reopening operation ofdoor. Should the passenger move out of the path of the beams while thedoor is reopening, the detector relay SR again picks up and closes itsmake contacts SR4 to energize the timing relay NU. This relay opens itsbreak contacts NU1 to prevent energization therethrough of the doorcontrol relay. In addition, make contacts SR1 close and break contactsSR2 and SR3 open. Opening of the contacts SR2 initiates a timing outoperation of the relay SRT. One-half second later this relay drops outto open its make contacts SRT1 and deenergize the auxiliary relay 70.The auxiliary relay then closes its break contacts 70--1 to complete anenergizing circuit for the door control relay 45 and this initiates aclosing operation of the door.

It may be desirable under certain conditions to prevent the timing relayNU from controlling the closure of the elevator car door. Thus, contactsmay be included which render inelective the contacts NUI ofl the timingrelay.v

TS1 is a time switch which opens its contacts during cervtain periods ofthe day when down-peak travel is expected.

-If the time switch is to be effective only at the lower terminal floor,it may be shunted by the mechanical switch y68 which is camoperated toopen only at the lower terf `minal iioor and ,which is closed for allother positions -of the elevator car.

Let it be assumed next that the safety edge SE is operated to hold thecontacts SE2 open for a period in lexcess of the dropout time delay ofthe relay NUA or that a person stands in the paths of the light beams tomaintain the contacts SRS open for such a period. Under suchcircumstances the relay NUA drops out and closes its contacts NUAl tocomplete with the contacts TNI and N1 an energizing circuit for the doorcontrol relay 45, to initiate a positive door-closing operation. Ifdesired the dropout of the relay may operate contacts for controllingthe doorclosing motor or solenoid to close the doors at slower thannormal speed and with increased force. Such operation of the door willbe discussed below. If the safety edge SE is released or the personmoves out ofthe paths of the light beams before the door closes, therelay NUA is reenergized and opens its contacts to restore the doorcontrol relay 45 to control by the safety edge SE and the light beams.However, if such restoration is not desired the relay NUA may be givensuflicient delay vin pickup to assure closure of the door.

Even though contacts NUAl are closed, if the switch 64A is open theclosure of the door is prevented if both safety edges SE and SEA areoperated. Under such circumstances the parallel contacts SES and SEA2are both opened to deenergize the door-close solenoid DC. If either ofthe safety edges thereafter is released the door resumes its closingmovement.

- Under some circumstances the efficiency of the elevator service may beimproved by expediting the dropout of the relay'NUA. Such dropout isexpedited by opening of the make contacts LWAl of the time-delay relayLWA.

' ,The time delay relay LWA may have a time delay in dropout of theorder of three seconds. lf the elevator car is-not fully loaded therelay LWA is energized through the load switch LW. If the elevator caris loaded in ex- 'cess of say 80% of capacity, the load switch LW opensto permit deenergization of the relay LWA. If desired the relay LWA mayhave an instantaneous drop out when deenergized.

Preferably the deenergization of the relay LWA is prevented while theelevator is at predetermined floors under predetermined tralcconditions. Thus if the elevator car is at the lower terminal floor theswitch 68A is closed. If `the elevator system at the same time isconditioned to provide down peak service the switch TSS is closed. Sincethe relay lLWA is maintained energized through theswitches 68A and TS3the relay is ineffective for shortening the dropout time delay of therelay NUA.

If the elevator car is away from both terminal oors the switch 68B isclosed. If the elevator system is conditioned at the same time toprovide up peak service the switch TS4 is closed.` Under theseconditions energization of the relay LWA is maintained through theswitches 68B and T54, and the relay is ineffective for shortening thedropout time delay of the relay NUA. During an up peaktraic ispredominantly in the up direction. Systems fory providing specializedelevator service during peak periods are -known in the art. For presentpurposes it will be assumed that a time switch closes contacts TS4egsoimb u ing circuit:

f 24 4during the periods of av day for which uppeaks are expected tooccur. u l

Thus if the elevator car is fully loaded at any floor during periodsother than up and down peak periods, or if the elevator car is fullyloaded at any floor other than the lower terminal floor during a downpeak period or if the elevator car is vfully loaded at a terminal floorduring an up peak period the door will be closed positively threeseconds. after such full loading occurs.

Positive closing of the door at the lower terminal tioor during a downpeak period usually is unnecessary. For this reason the relay NUA may beenergized through an alternative circuit which includes a switch TS7closed during down peak periods and a cam-operated switch 68C which isclosed only when the elevator car is at the lower terminal floor.

Next let it be assumed that the switch 67 in Fig. 4 is closed to permitassignment of the elevator car A under certain conditions to reverse atan intermediate landing. The conditions may be such that no down floorcall or no car call is registered for a floor above such landing andthat no up floor call is registered for such landing or for any higherlanding while the elevator car is set for up travel and is approachingsuch landing.

For illustrative purposes, let it be assumed that the elevator car A isapproaching the fourth oor and that a down door call for the fourth ioorconstitutes the only call registered in the system. Under suchcircumstances, the down floor call registering relay 4DR is picked upand the break contacts 4DR2 (Fig. 4) are open by a sequence clear fromthe foregoing discussion.

As the elevator car nears the fourth oor, the brush 66 engages thecontact segment K4 to complete the follow- The relay J closes its makecontacts I 1 (Fig. 2) to complete with the make contacts M1, anenergizing circuit for the relays E, F and G. These operate in themanner previously described to stop the elevator car at the fourth oor.In addition, break contacts J2 open. As the elevator car stops at thefourth floor, the make contacts M7 of the running relay also open todeenergize the up-pref- F erence relay W. Since the up-preference relaycloses its break contacts W2 to energize the down-preference relay X,the elevator car now is assigned for down travel.

u Finally, the reversal relay J opens its break contacts' J3 to preventenergization therethrough of the timing relay 70HT. The floor callstopping relay resets and opens its make contacts K2 slightly beforecontacts J3 reclose. Consequently, the relay 70HT is ineffective forcontrolling the non-interference time.

The non-interference time of the elevator car now is t controlled solelyby the timing relays 70T and SRT. Conu shunted by a manual switch 69A.The contacts M4 may then, be given 'a slight time delay in closing.Under these circumstances the brush 58 is positioned to engage the`contact segment f4 when the elevator car stops at the fourth oor.Closure of the contacts X5 when the elevator car is set for down travelenergizes the relay K and the relay K is then deenergized by reset ofthe registering relay 4DR following closure of the contacts M4. Themomentary closing of the contacts K2 operates in the manner previouslydescribed to provide a minimum noninterference'time of two seconds.However, it will be assumed that the switch 69A is open and that areversal of the car at an intermediate floor provides a minimumnon-,interference time of one-half second. 'i

As the elevator car A on its up trip approaches the upper terminal orfifth floor, the brush 12 (Fig. 2) engages the contact segment a5 tocomplete the following energizing circuit for the car-call stoppingrelay:

L+, a5, 23, W3, TT, M3, L The car-call stopping relay operates in themanner previously discussed to stop the elevator car accurately at theupper-terminal floor.

As the elevator car A reaches the upper-terminal oor, the mechanicalswitch 63 (Fig. 4) opens. Consequently, the elevator car A cannot startfrom the upper-.terminal oor untily it is started by its upper-terminaldispatching device represented by the'contacts TS1'. It will beunderstood that the upper-terminal dispatching device may be similar tothe dispatching device discussed for the first iioor. For presentpurposes it will be assumed that the contacts TS1 operate for theupper-terminal dispatching oor in the same manner by which the contactsS1 operate for the lower dispatching iloor.

As the elevator car reaches the fth oor, the limit switch 36 (Fig. 2)opens to deenergize the up-preference relay W. This relay opens its makecontacts W1, W3, W5, W6, without immediately affecting the operation ofthe system. However, opening of the make contacts W4 deenergizes theholding coils for the car-call push buttons, and these are reset. Inaddition, closing of the break contacts W2 completes the followingenergizing circuit for the down-preference relay:

L+, U6, wz, X. s1, as, L-

The down-preference relay X closes its make contacts X1, X3, X4, X5 andX6 and opens its break contacts X2 to condition the elevator car fordown travel.

I t will bey assumed next that the dispatching device for the upperterminal iloor closes its contacts UTSl (Fig. 4) and that the timingrelay has closed its break contacts 70T2 to complete an energizingcircuit for the starting relay 80. The loading relay of the dispatchingdevice for the upper-terminal floor operates the contacts TNl to controlthe door-control relay 45 in the same manner by which contacts N1control the door-control relay at the lower terminal oor. The closing ofthe doors coupled with the closing of the make contacts 80-1,k completesthe following circuit for the down switch D and thev car-running relayM:

The car-running relay Mv operates in the manner previously described toprepare certain circuits for subsequent operation.

Upon energization, the down switch D closes its make contacts D1 torelease the brake 17. In addition, make contacts D2 and D3u close toenergize the generator eld winding 297C in th-e proper direction fordown travel of the elevator car. Closure of the make contacts D4completes an energizing circuit for the speed relay V. This relay closesits make contacts V1 to shunt the resistor R1 and opens its breakcontacts V2. The elevator car now is conditioned for movement in thedown direction at full speed and moves away from the upper terminalfloor.

Closure of make contacts. DS establishes a holding circuit around thecontacts 8 0-.1 and X1. Opening of break contacts D 6 has no immediateeffect on the operation of the system.

It will be understood that as the elevator car leaves the upper terminaloor, the limit switch 34 (Fig. 2) and the switch 63 (Fig. 4), reclose.

It will be assumed next that a passenger in the elevator car operatesthe car-all push button 3c for the purpose of registering a car call forthe third oor. This button connects the contact segments a3 and h3 tothe bus L+. Also contacts 3oz; and 3cy open.

When the brush 40a reaches the contact segment h3, an energizing circuitis established yfor the car-call sito ping relay TT as follows:

L+, 3c, h3, 40a, X3, TT, M3, L-

Consequently, the relay closes its make contacts TTI to energize throughthe contacts M1 the holding relay G and the inductor relay E. Theholding relay G closes its make contacts G1 to establish a holding'circuit around the contacts TTI.

When the slowdown inductor relay E reaches the inductor plate DEP forthe third oor (Fig. l), the contacts E2 open to deenergize the speedrelay V (Fig. 2). The speed relay opens its make contacts V1 tointroduce the resistor R1 in series with the generator field Winding29C. The elevator car now slows to a landing speed, In addition, thebreak contacts V2 close to complete arr energizing circuit for thestopping inductor relay F.

When the stopping inductor relay F reaches the inductor plate DFP forthe third floor, the contacts E; open to deenergize the down switch Dand the carrunning relay M. The down switch D opens its make contacts D1to permit reapplication of the brake 1,1. Make contacts D2 and D3 opento deenergize the gen-1 erator iield winding, and the elevator car Astops ac-AV curately at the third floor. Opening of the make contacts D4and D5 and closing of the break contacts D6, have no immediate effect onthe operation of the system. As the elevator car comes to a stop thebrush 40a may. pass the contact segment h3 slightly to deenergize therelay TT. Y

The car-running relay M opens its make contacts M1 to deenergize theinductor relays and the holdingy relay G. The holding relay G in turnopens its make contacts G1 to prevent subsequent energization therethrough of the inductor relays.

The make contacts M2 open to initiate an opening operation of the doors.The opening and closing of the' doors will be understood lfrom theprevious discussion: thereof.

The car-running relay M also opens its make` contactsl M5 to start atiming-out operation of the timing relay 70T. Opening of make contactsM3 and M5 and closing of break contacts M4 have no immediate effect onthe operation of the system. Break contacts M6 close to illuminate thelamps LAI and LA2. When thetilllillgr relay 70T drops out, the breakcontacts 70T2 (Fig. close to energize through the switch 63 the startingrelay 80. The starting relay operates in the manner previously describedto start the elevator car down from the third` floor. It will berecalledv that the drop out of the relay 70T may be expedited by entryor departure of a. passenger relative to the car before the time delayof theA relay expires.

Let it be assumed that instead of a car call a down floor call wasregistered for the third tloor by operation of the push button 3D (Fig.3). Such operation energizes the down floor-call storing relay 3DRwhichl closes its make contact 3DR1 to establish a holding cir-v4 cuitaround the push button 3D. The contact segment f3 and correspondingcontact segments for the remain-y ing elevator cars of the system areconnected through the make contacts 3DR1 to the bus L+. Also contacts3DR2 and 3DR3 (Fig. 4) open without aiecting the operation of thesystem.

As the elevator car A approaches the, third floor in the down direction,the brush 58 reaches the contact seggV ment f3 to complete an energizingcircuit for the floor call stopping relay K as follows:

L+, 3DR1, f3, 58, X5, K, L-

The relay K closes its make contacts K1 (Fig. 2) to energize the holdingrelay G and the slowdown inductor relay 'E through the contacts M1.These relays operate'

